PHILADELPHIA (AP) — A man stopped for an expired car registration sticker traded gunfire with police Tuesday during a highway chase that ended with a fiery crash involving a school bus and a trooper with a gunshot wound in his shoulder, police said. Two people who were in the car when it was stopped were in custody, but Philadelphia police were searching for two more following the midmorning crash on a downtown highway, authorities said. When police first stopped the car, they asked the four people inside to exit the vehicle, but one of the suspects jumped back in and took off, investigators said. The suspect again started shooting, while Casey returned fire, authorities said. “The governor was glad to hear that Trooper Casey believes he will be able to be home with his family for Thanksgiving,” Wolf’s office said in a statement. “I saw a gunfight down here,” he said while pointing to Interstate 676 from an overpass. “I came out, there were cops down there, shooting at someone, and then someone was shooting at them.” “I heard what I thought was gunfire, and it turns out that it was,” he said. “When I came out, there was a gunfight going on and that car had already hit the bus.”